Boswellia Serrata for Cerebral Radiation Necrosis After Radiosurgery for Brain Metastases
Rituraj Upadhyay, A.N. Elguindy, Laura Salts, Kari Donovan, Soma Sengupta, Kyle Wang, Pierre Giglio, Samuel Chao, Arnab Chakravarti, Raj Singh, Sasha Beyer, Raju R. Raval, Evan Thomas, Joshua D. Palmer
Abstract
PURPOSE: Radiation necrosis (RN) is a dose-limiting toxicity of stereotactic radiosurgery (SRS) for brain metastases. Oral corticosteroids are not optimal for long-term management, given multiple side effects. Boswellia serrata (BS) is an over-the-counter supplement traditionally known for its anti-inflammatory properties and has recently been shown to reduce cerebral edema. We evaluated the response rates of BS in a series of patients with RN after SRS for brain metastases. METHODS AND MATERIALS: We identified patients who developed any grade RN after SRS and received BS for ≥2 months at a target dose of 4050 to 4500 mg daily. The primary endpoint was objective response rate (ORR), including complete response (CR) or partial response (PR), defined as ≥30% decrease in edema volume on T2-fluid-attenuated inversion recovery magnetic resonance imaging from baseline. RESULTS: A total of 100 patients received BS, of which 94 patients with adequate follow-up were included. The median SRS dose was 24 Gy in 3 fractions, and 44%, 47%, and 9% of patients had grade 1, 2, and 3 RN, respectively. The best response was CR in 12% and PR in 48%, while 28% had stable edema and 12% had progression of edema. The overall ORR was 59.6% (95% CI, 48.9%-69.6%). ORR was 62%, 63%, and 33% for grade 1, 2, and 3 RN, respectively. The median duration of response in patients with CR or PR was 13.9 months (IQR, 9-23). Among 69 patients (73%) who never received steroids, received prior steroids only, or had a stable or decreasing steroid requirement of ≤4 mg per day of dexamethasone for at least >1 week prior to starting Boswellia, the ORR was 63.8%. Fourteen percent of patients had National Cancer Institute Common Terminology Criteria for Adverse Events grade 1, and 2% had grade 2 gastrointestinal toxicity. A total of 67% of patients remained on BS at the last follow-up. CONCLUSIONS: Our study suggests that BS is a safe and feasible treatment option for grade 1 to 3 RN after SRS. Further prospective studies comparing BS with a placebo are warranted.